How can I sort list of custom object by multiple properties of objects

Question

Can someone help me to sort list of my custom objects by multiple parameters.
I want to sort it by date1 and date2 and optionally b all three properties but whatever I try it fails :(
My object:

class MyObject : NSManagedObject{
   @NSManaged var date1:NSDate
   @NSManaged var date2:NSDate
   @NSManaged var key:Int
}

This is my failed tries to sort list of those objects:

var sortedArray1 = sorted(unorderedList, { (o1: MyObject, o2: MyObject) -> Bool in{
            return o1.date1 == o2.date1 ? (o1.date2 < o2.date2) : (o1.date1 < o2.date1)
        }

        var sortedArray2 = sorted(unorderedList, { (o1: MyObject, o2: MyObject) -> Bool in
            return (o1.date1.compare(o2.date1) == NSComparisonResult.OrderedAscending) == (o1.date1.compare(o2.date1) == NSComparisonResult.OrderedAscending) ? (o1.date2.compare(o2.date2) == NSComparisonResult.OrderedAscending) : (o1.date1.compare(o2.date1) == NSComparisonResult.OrderedAscending))
        });

Could you please specify in details the criteria for sorting. — Abdullah
– Abdullah, Commented Mar 30, 2015 at 7:40
date1 and date2 are date with time. This is some from and to properties. I need to sort list by those two properties to get something like like: 04:00to05:00, 04:00to05:30 etc. And key is simple 1,2,3... but that key can also be nil so primary sorting should be by date properties. — 1110
– 1110, Commented Mar 30, 2015 at 7:52
So sort by date and if dates are equal get into account the keys. For dates you could not use < or > operators as these are not provided by Swift except you have defined it yourself. Same for == or != operators. If you have not and wants to do it, I will request you to look at this framework github.com/abdullah-chhatra/iDate. — Abdullah
– Abdullah, Commented Mar 30, 2015 at 7:55
Ok if I want to avoid sorting by key so just by dates how can I sort this? — 1110
– 1110, Commented Mar 30, 2015 at 7:57

Abdullah · Accepted Answer · 2015-03-30 09:29:01Z

1

Try this out and let me know:

unorderedList.sorted({
    if $0.date1 < $1.date1 {
        return true
    } else if $0.date1 == $date2 {
        return $0.date2 < $1.date2
    }
    return false
})

public func == (left: NSDate, right: NSDate) -> Bool {
    return left.isEqualToDate(right)
}

public func != (left: NSDate, right: NSDate) -> Bool {
    return !left.isEqualToDate(right)
}

public func > (left: NSDate, right: NSDate) -> Bool {
    return left.compare(right) == NSComparisonResult.OrderedDescending
}

public func < (left: NSDate, right: NSDate) -> Bool {
    return left.compare(right) == NSComparisonResult.OrderedAscending
}

edited Mar 30, 2015 at 9:29

answered Mar 30, 2015 at 8:03

Abdullah

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4 Comments

1110 Over a year ago

I get: NSDate is not a subtype of NSString. Where should I put those functions?

Abdullah Over a year ago

Put those in any file of your project outside of any class.

1110 Over a year ago

Results are wrong: 01:00to04:00, 02:00to04:00, 01:00to04:00, 01:00to04:00, 03:00to04:00

Abdullah Over a year ago

Try the new code. You could try to manipulate the conditions to make it work for you.

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